Rock drill chuck



March 18, 1958 T. A. TAYLOR 2,327,019

ROCK" DRILL CHUCK Filed May :5, 1955 2 Sheets-Sheet 1 20 FIGZ IN VEN TOR. THOMAS A. TAYLOR FIG. I

TTORNEY March 18, 1958 T. A., TAYLOR 2,827,019

ROCK DRILL CHUCK Filed May 3, 1955 2 Sheets-Sheet 2 INVENTOR.

' THOMAS A. TAYLOR ROCK nuns. ennui Thomas A. Taylor, Brecksville, Ohio, assignor to Westinghouse Air Brake Company, Pittsburgh, P2,, a corporation of Pennsylvania Application May 3, 1955, Serial No. 505,575

4 ll-aims. (G. 121-32) This invention rel-ates broadly to rock drills, but more particularly to an improved rock drill front end equipped with a dust collecting device.

One object of this invention is to provide a rock drill front housing of the dust collecting type with simple and positive means for maintaining the drill steel chuck bearings free of drilling dust.

Another object of this invention is to provide a rock drill front end with single and efiicient means for rotationally locking the drill steel chuck to the chuck sleeve and also limiting the slidable movement of the chuck at least in one direction.

Another object of this invention is to provide a rock drill front end with common means for rigidly locking the drill steel chuck against rotation relative to the chuck sleeve and resiliently limiting axial movement of the chuck at least in one direction.

Another object of this invention is to produce a rock drill front end with the drill steel chuck and other movable parts arranged and disposed in a manner reducing to a minimum the number of bearings subjected to drilling dust, and providing such bearings with simple and efficient dust barriers preventing admission of dust or other abrasive material thereon.

Another object of this invention is to provide such a front housing with simple and efiicient lubricating means for the drill steel chuck bearings, without danger of the lubricant becoming mixed with drilling dust to form a lapping compound causing excessive wear of the bearings.

Other objects and advantages more or less ancillary to the foregoing reside in the specific construction and aggroupment of the elements peculiar to this structure, as will become apparent from a more complete examination of this specification.

In the accompanying drawings:

Fig. 1 is a longitudinal sectional view of a rock drill front end embodying the invention.

Fig. 2 is a view similar to Fig. l, but illustrating a modified construction.

Figs. 3, 4, 5, 6 and 7 are cross sectional views taken on lines 3-3, 44 5-5, 66 and 77 respectively in Fig. 1.

Fig. 8 is a cross sectional view taken on line 88 in Fig. 2.

Referring to the drawings, 19 designates a rock drill front housing having a bore centrally therethrough and defining a cylindrical inner wall 11. Except for a large counterbore 12 formed at its outer end and defining an annular shoulder 13, this bore is of uniform diameter ice provided with internal splines 18 in mesh with corresponding splines 19 formed on the stem 20 of a piston, not shown, reciprocably mounted within the rock drill in the usual manner. This piston is also operatively associated with a rotation mechanism, well known in this art, through which reciprocatory motion of the piston also eifects its rotation in one direction, which rotation is transmitted to the sleeve 14 by the interengagement of splines 18 and 19. The inner end of sleeve 14 is formed with a bore or cylindrical recess 21 extending centrally therethrough to end at the inner ends of the splines 18. This recess which is of uniform diameter throughout has mounted therein in slidable guided engagement therewith, a cylindrical drill steel chuck 22 which when in its innermost position within the sleeve 14 has its outer end substantially flush with the outer end of bushing 15.

The outer end of chuck member 22 is internally threaded as at 23 to receive the threaded inner end 24 of a polygonal stem member 25 extending axially beyond the front end of housing 10, and provided with an integral circular flange 26 engageable with the outer end of the bushing 15 for limiting inward movement of the chuck 22 into the sleeve 14. Over flange 26 is preferably mounted a rubber disk 27 engageable with the free end of the housing 10 to form a dust tight joint therewith. This disk also serves as a cushion for a sleeve coupler 28, of polygonal internal cross section, with its inner end portion slidably mounted on the stem 25 and loosely resting on the disk 27. The outer end portion of this coupler forms a polygonal socket adapted to receive the shank end of a drill steel 29.

In order to rotationally lock the chuck 22 to the sleeve 14, their interengaging bearing surfaces are provided with longitudinal recesses or grooves 31; and 31 respectively, peripherally spaced equally and of semi-cylindrical cross section, which when radially aligned accommodate cylindrical pins or dowels 32. As clearly shown in Fig. 1, the grooves 31 and dowels 32 are of equal lengths, while the grooves 36 are substantially longer than the dowels to enable limited axial movement of the chuck relative to the sleeve. Preferably this axial movement is checked inwardly by the flange 26 of stem 25 engaging bushing 15, and outwardly by the inner ends of the dowels 32 engaging the corresponding ends of the chuck grooves 39. However, the dowels could well be made to engage both ends of the grooves 35 to limit axial movement of the chuck in both directions. To facilitate assembly, the sleeve grooves 31 extend to the outer end of the sleeve and are covered by the inner end of bushing 15, which retains the dowels within the grooves 31.

Between the inner ends of its splines 18 and its extreme outer end, sleeve 14 is provided with an oblong orifice 33 extending through its wall and opening into a relatively wide annular groove 34 formed within the housing 11 and extending around the sleeve 14. This last groove also opens into a relatively large dust collecting passage 35, formed within the wall of housing 19, which is threaded to connect with one end of a flexible conduit, not shown, which has its other end connected to the vacuum side of a dust collector. Oblong orifice 33 is in constant communication with the usual drill steel hole 36 through a similar hole 37 provided through stem 25 and a dust passage 38 provided within the chuck 22.

In order to assure proper lubrication of the chuck member 22 within bushing 15, the latter is provided with internal and external annular grooves 39 and 40 connected by one or more radial ports 41, with the external groove 49 connected to a passage 42 formed within the wall of housing 19. This passage, which is generally controlled by the throttle valve controlling the operation of the rock drill, conveys oil laden compressed air to the interior or" bushing 15 via groove 39.

V of' the chuck housing 10 to prevent admission of drilling.

1,, A. j 7 2,827,019 a V a a 3 V a 4 s t On each side of the du' t collecting groove 34; the surfaces between the chuck member and the sleeve, such sleeve 1d is provided with annular grooves 43 and 44' access cantake place only over the marginal edges of also connected with the passage 42 through radial ports the l ng r fi To prevent h occurrence r at V 45. On each end of the, oblong orifice 33, the sleeve 153 least limit it to a minimum, the crescent-shaped grooves has its inner wall formed'with 'crescenhshap'ed grooves" 5 6 and 47 have been provided adjacent the longitudinal 46'and47 connected' 'with the annular groove 43 and 44' ends of the orifice 33, thereby causing compressed air respectively through radial ports- 48: Another radial fiOWiilg 0f leaking out 051115 grooves 45 and 47 t0 estabport'49 connectspassage 42. with the inner end portion lish barriers to the longitudinalseepage of dust onto the of sleeve 14to assure proper lubrication of that'portion bearing surfaces between chuck member 22 and sleeve 14. ()f h l e i hi h i 19; 7 10 will be understood that in the present construction; 7

no dust barriers had been provided, the relatively all amounttof dust capable of escaping from the dust e Jove 34 could not materially affect the relatively large Inthe' modification shown in Fig. 2, the sleeve 14 is the same as in Fig. l, but the dowels 32 have been replaced by relatively stiff compressionsprings 132 which rigidly lock the chuck member 122 against rotation rela- 'Y bearing Surfaces bsiweefi Sleeve 14 and 110118- tive tothe' sleeve, andby engagement of the inner ends 15 331 Wfifds, ihe eXtenSien 6f the ve 1 of' the longitudinal grooves'30 with the springs resiliently w edbsifimialiy the flefi end Of 7316 hfiusifig P limit the outward movemenfiof' the chuck member. "In vides for better and longer wearing rotary bearing surthis modifiedconstruction the chuckjrnember 122'has its faces between the sleeveand housing. Similarly, since outer end formed with an externakannular flange 50 the chuck member 22 is capable of, only'relatively'short engageable with bushing l5forlim'iting' inward moveaxial m v Or Slrbkes Within the Sleeve ment of 'the chuck member into sleeve 14. Its outer small amount of dust which may escape over the longiend portion is also provided 'with' a flat bottom cylintudinal edges of the oblong orifice 33 is not likely to dricalbore 51 having fitted'therein a chuck bushing52. materially aifect the relatively large sliding bearing'sur," This'bushing' is locked to thechuckfby means of a faces between the chuck and sleeve. 'In other words, press'fit or the like, and internally is of'polygonal cross 25 by rotationally locking the chuck to the sleeve thr'ough section to slidably but non-'rotataoly receive the'shank the dowels 32 and limiting, outward movement of the of the drill steel 29'. Bushing 52' also has a head 53, chuck also the same dowels, the chuck 22 is provided resting on the outer end of the'chuck and carrying a with better and longer wearing bearing surfaces with rubber disk or shield 127 adapted to' engage the end the sleeve id.

The operation ofv the modified 'construction shown in dustinto the housing. From the bottom of the bore 51 Fig. 2 is the same. as explained above, except that the comextends a dust passage 133 which has its outlet end' pressiontsprings 132 while rigidlylocking the chuck memopening in the oblong orifice 33. Since the rest of this her 122 against rotation relative to the sleeve 14, also modified construction is exactly the'same as above de-'. 35 act as cushion members for resiliently limitingoutward scribed and shown in Fig. l, the corresponding parts movement of the chuck member. In normal drilling thereof have been given like symbols. operation, such feature is not important because the- The operation of the chuck mechanism shown-in Fig." rock drill is generally fed'to the work with the drill l is as follows: As the'rock drill is actuated'in the usual, steel pressed against the face of the rock or bottom of manner to effect the reciprocatory motion of the piston 40 the hole, and the chuck cannot travel but a very short 'and its stem 29, impacts in rapid succession are delivered distance upon each impact of the piston stem thereon. on the inner end of the chuck member 22 by the piston However, when the rock' drill is accidentally operated stem 2 and rotation from the piston stem is also transwith the drill steel away from the face of 'therock or mittcdj to the chuck member through the chuck sleeve bottom of the-hole, then the chuck member 122 respona 14. From chuck member 22 impacts and rotation are sive to the impacts of the piston stem 2%, is free to travel transmitted to the drill steel 29 to drill allele in the outward until it is checked-by the bottom ends of the rock in the usual and well known manner. Concurrently lOllgiiudifiai gYOOVeS 3i) g g g p i gs 32.

oil laden compressed air is conveyed by passage 42 into The details of structure and arrangement of, parts annular grooves 39, 46, 47 andport49 to provide efiishown and described may be variously changedtand;

cient lubrication of the bearing surfacesadjacent such 50 i d Without departing from the spirit and scope grooves and port, V Of theiinvention as herein claimed. a

As the dust collecting device is turned on,'a vacuum I Claim: 7 t

or suction is created in the dust groove 34 through the 111 a IOck drill, 3 Chuck housing, a Piston P cgnduit, not hown, connected to the dust passage 35, cable and rotatable in said housingya ChllClCSlSeVfl axially thereby drawing air, dust and cuttings into'the groove milled in Said housingtand 7 splinesengagemenflwith 34 through h ip Steel hole 35 Stem i3 7 l said piston for rotation therewith, a drill chuck slidaole passage 33- d bk ifi 33 P grooves: i within said sleeve, interengaging bearing surfaces on said dust and cuttings are drawn into the dust collecting'de- Chuck and Sleeve, radially aligned longitudinal recesses vice through the conduit connected, to the passage 35.' The only possibility for the abrasive dust to gain; access to the bearing surfaces betwcen the sleeve 14 and housing 16,: is, over the marginal edges of the groove-34. However since compressed air is admitted into annular grooves and 4-4 located adjacent the groove 34 on Sald Shdable movement one dlrectlonboth sides thereof, it will, as it leaks out of'thegrooves 55 recesses being longer than said pin to enable: slidable Within said surfaces, a dowel pin within said recessesrotationally locking said chuck and sleeve, one of saidmovement of said chuck and having one end thereof: engageable with the corresponding end of said pinto limit 2. In airock drill, a chuck housing, a-piston recipro- 44 establish dustpbarriers preventing th e dust cable and rotatable in said housing, a chuck sleeve axially from seeping out of groove 34 onto the bearing-surfaces of the sleeve and housing.

It willrbe noticed that the length of the orifice 33v is flidable Within Said Sleeve, means rotationally locking greater than the p'ossible'axial travel of the chuck mem- Said Chuck and Sleeve, Sliding beafingtsurfaws 011 saidr b zz, h le th f hi h i d i d b th unoechuckand sleeve, a dust groove -on one of said surfaces? 7 cupied' portion of the longitudinal grooves 34 relative surrounding said sleeve and adapted to be connected to the dowels 32, thereby assuring constant registration of r asuction source, a dustpassage within said chuck, an ori-, the outlet end of chuck passage 38 With the orifice 33s. fice through'the wall of said sleeveconnectingrthe outlet As'to: the possible access of dust on the sliding bearing end of said passage'with said groove, and passages conretained' in said housingnand in splineengagement with said piston 'for'rotation therewith, a drill steel chuckz nected to a source of compressed air opening on said sur faces adjacent said orifice.

3. In a rock drill, a chuck housing, a piston reciprocable and rotatable in said housing, a chuck sleeve axially retained in said housing and in spline engagement with said piston for rotation therewith, a drill steel chuck slidable within said sleeve, and a removable spring member longitudinally between said chuck and sleeve rigidly preventing relative rotation therebetween and resiliently limiting said slidable movement in at least one direction.

4. In a rock drill, a chuck housing, a piston reciprocable and rotatable in said housing, a chuck sleeve axially retained in said housing and in spline engagement with said piston for rotation therewith, a drill steel chuck slidable within said sleeve, and spring means between said chuck and sleeve rigidly preventing relative rotation therebetween and resiliently limiting said slidable movement in at least one direction.

References Cited in the file of this patent UNITED STATES PATENTS 

